Yawning is an action humnans are very
familiar with, yet this behavior is not unique
to our species. Most vertebrate animals
demonstrate yawning behavior. The cause of
yawning is still uncertain, but yawns across
vertebrate species seem to be concentrated
around transitions between sleep and activity.
Our most popular companion animal, Canes
familiaris, also has periods of yawning before
and after sleep. Dogs are naturally social
living creatures and rely extensively on body
language as a form of communication between
group members. Behaviorists have suggested that
some dog yawns are part of this visual
communication system.

The object of this observational study was
to confinn that dogs have two main yawn types: a
"rest" yawn that occurs between sleep-activity
transitions, and a "social" yawn occurring
during social interactions. Social interactions
in this study referred to both dog-dog and
human-dog interactions. Communicative yawning is
performed to displace anxiety in an individual
dog or to pacify aggression or excitement in
other individuals. The frequency of rest yawns
was predicted to be higher than that of social
yawns.

Both yawn types were morphologically the
same, so the context of a yawn was used to
indicate whether the yawn occurred for rest or
communication. Even when recording the context
of a yawn, distinguishing between displacement
and pacification intentions was very difficult.
Therefore, yawns motivated by displacement or
pacification were collectively considered social
in function.

Because social yawns only occur in the
presence of other individuals, dogs were
observed in the social settings of dog daycare
and obedience classes. Individual dogs were
observed for 15-20 minutes. Some observations
were videotaped, but the majority were taken in
real time. Behaviors immediately preceding and
following a yawn were recorded using an ethogram
tailored to rest, displacement, and pacification
behaviors.

This study indicated that the majority of
dog yawns occur during social interactions and
not during sleep transitions. Using the yawn as
a gauge to indicate if a dog is anxious or
relaxed is one step towards more effective
communication between dogs and humans. A yawn
can act as a behavioral cue for dog handlers,
trainers, owners and anyone concerned with
canine welfare.

CHAPTER 1

Introduction

With mouth stretched wide, lips pulled back,
and every sharp, shining tooth on display, the
yawning dog may look a bit intimidating. While
it may seem like he is intentionally showing off
his considerable dental weaponry, the dog's yawn
is controlled by reflex, a trait shared with
human yawns. Despite physiological similarities,
dog yawns are not necessarily synonymous with
those of humans. Dogs yawn less frequently than
humans do. A dog at the veterinarian's office
will yawn an average of four times in an hour,
compared to the 23 yawns per hour of a college
student during a lecture (Phillips &
Hoffman, 2000). Unlike humans, dogs also yawn
outside of sleep/activity transitions. The
possibility exists that all dog yawns are rest
yawns, as in human beings. This study
investigates the alternative, that dogs yawn in
both restful and social contexts, and that some
dog yawns serve a communicative function. I
predict that dogs yawn more often during rest
than during social situations. Few behavioral
studies have dealt with the activity of yawning;
most ethological yawning studies are based on
primate subjects. In one such study, 90% of all
yawns occurred during transitions between rest
and activity and 10% during social contexts
(Deputte, 1994). I expected to find a similar
proportion among dog yawns.

Yawning is a basic behavior every human is
familiar with. Yet the yawn is not unique to
Homo sapiens or to Canis familiaris, the
domestic dog. Yawning has been observed in a
variety of vertebrate species. Baenninger (1987)
recorded yawns in Siamese fighting fish, and
yawns have also been observed in ostriches
(Sauer & Sauer, 1967) and mammals. Mammalian
yawns occur more frequently among carnivores
than among herbivores (Baenninger, 1997). Yawns
have been observed in rats (Anias et ai, 1984),
lions (Baenninger, 1987), canids (Beerda et al,
1997 & 1999; Bekoif 1974; Lund et ai, 1999)
and in several of the non-human primates,
including chimpanzees, mandrills, mangabeys and
macaques (Aureli & de Waal, 1997;
Baenninger, 1987; Deputte, 1994).

Even though yawning behavior occurs across
all the vertebrate classes, the cause and
physiological benefit of yawning remains a
mystery. The motivation behind a yawn may not be
the same for all animals. Suggested reasons for
yawning include elevation of blood oxygen levels
(Greco et ai, 1993), evacuation of the tonsillar
fossae (McKenzie, 1994), a mechanism for arousal
(Askenasy, 1989; Baenninger, 1997; Greco et ai,
1993), and social communication that influences
the behavior of other individuals (Rugaas, 1997;
Smith, 1999). High daily yawning frequency has
been selectively bred for in a line of
laboratory rats, demonstrating that yawning is
at least partially influenced by genetics (Anias
et ai, 1984).

Yawning patterns appear to follow a
circadian rhythm (Anias et ai, 1984; McKenzie,
1994) with peaks during sleep/wake transitions
(Deputte, 1994; Greco et ai, 1993). However,
Baenninger (1987) observed no yawns immediately
before or after sleep in zoo kept mandrills.
Rather, he found both mandrills and lions yawned
with the highest frequency during periods of
arousal, such as the hour before feeding time.
For wild animals kept in a low stimulation
environment, feeding time is probably the most
stimulating part of their day. This finding
supports the idea that yawns function to arouse
the nervous system in anticipation of events.
Baenrnnger also found that male Siamese fighting
fish rarely yawned when kept isolated. He then
paired the fish with other male Siamese fighting
fish - the fish could see each other through a
Plexiglas barrier - and observed that yawning
frequency increased significantly in both
members of the pair.

Humans and other animals have also
demonstrated increased yawning during
transitions in arousal levels. Human subjects
yawn with the highest frequency the first hour
aller waking and the hour proceeding sleep. We
also have peaks of yawning during activities
where periods of physical relaxation and mental
alertness alternate, such as when sitting in
lecture or driving in the car (Greco et ai,
1993). In primates, yawning was induced in
mangabeys and macaques during social
interactions that involved, ". . an increase in
arousal or a conflict of drives." (Deputte,
1994). Canids also show this relationship
between yawns and stimulating events. Dogs that
were chronically stressed and then presented
with a mild disturbance, such as the slamming of
a door, yawned with a higher frequency than dogs
kept in low stress environments (Beerda et ai,
2000). The authors of this study concluded that
yawns were an indicator of higher than normal
arousal levels in the chronically stressed
animais. Dogs also yawn as activity decreases.
Videotaped observations of dogs with separation
anxiety revealed an increase in yawning just
prior to rest (Lund & Jorgensen, 1999).
According to the arousal hypothesis, this
pre-sleep yawning is an effort to stimulate the
brain and ward of sleep (Baenninger, 1997).

Some attention has been given to the idea
that yawns can serve as behavioral indicators of
well-being in animals. Yawning has been used to
index social stress in chimpanzees kept in high
density living conditions (Aureli & de Waal,
1997). When the chimps were housed in indoor
runs where space was limited, behavioral
indicators of stress - both yawning and body
scratching - occurred more often than when the
chimps had more social space. In a study related
to the research on chronic canine stress, yawns
were an indicator of acute stress in dogs
(Beerda et al, 1998). Yawns that occur outside
arousal transitions, as observed in these
studies, may have a communicative function
(Redican, 1975). The communicative value of
yawning has been proposed by several authors.
Although their studies confirm that yawns occur
in social contexts and that motivation for
yawning exists outside of activity transitions,
true communicative yawning has yet to be
confirmed.

Animals that live in social groups rely on
communicative behaviors to reduce conflict among
group members (Dunbar, 1979). In many ways, the
social system of dogs is similar to that of
people. Like humans, dogs live in groups that
are essentially an extended family, their young
require extensive parental care, and they work
as a group to provide for and raise the young.
Also, dogs use play as one method of developing
social skills, and they communicate extensively
through a variety of vocal and non-vocal
signals. Humans use complex verbal signals to
communicate with one another, but other animals
are incapable of speech and so naturally must
use other mediums of communication. Social
living animals, like the dog, especially have a
highly developed system of non-verbal
communication. The most complicated aspect of
canine communication is that of body language.
Dogs use subtle cues in their communication,
cues humans may not be aware of, but can learn
to detect.

Dogs subtly change their body posture and
position of mouth, cars, eyes and tail to
communicate with each other. Their body language
conveys information to other dogs about
dominance, confidence, inferiority, fear,
friendliness, or intention to play. Because they
must be able to receive these signals as well as
send them, dogs are acutely aware of subtle
changes in behavior and posture, both in their
canine and human counterparts (Fox, 1971). Just
as humans talk to dogs using human language,
dogs try to communicate with us using dog
language. This communication barrier can be an
obstacle preventing a happy, healthy
relationship between man and dog. "In
particular, the combinations of different types
of signals (visual, acoustic, tactile and
olfactory) must be investigated to sec how they
combine to establish, reinforce and end
interactions [between man and his pet]."
(Mulot & Filiatre, 1986).

Because many of the behaviors dogs offer us
are presented for purposes of communication, it
is reasonable to wonder if yawns are included in
these communicative behaviors. Smith (1999)
suggests two functions for yawning: individual
physiological benefit, and communication, where
the behavior of another individual is influenced
by a yawn. In his study on primates, Deputte
(1994) distinguished between two yawn types. He
found the 'rest yawn' to occur during
transitions between sleep and activity and the
'emotion yawn' that followed social interactions
and expressed anxiety, conflict, or threat. Both
yawn types were morphologically similar and
could only be classified based on context.

Yawns occurring in a social context have
been further divided into displacement and
pacification behaviors. Displacement activities
occur during conflict between two motivational
states, for instance, the fight or flight
response. When unsure of which response to give,
the animal will perform a behavior completely
unrelated to the situation. "The individual
tries to achieve a sense of security by
performing an activity which it feels safe with
and connects with pleasure." (Abrantes, 1997).
In primates, yawning and body shaking are two
common displacement activities that increase in
frequency during stressful situations
(Macstripieri et al, 1992). Dogs also have
specific displacement behaviors. Besides
yawning, canine displacement activities include
sexual behaviors, territory marking, and muzzle
nudging. The yawns observed in the dog studies
by Beerda et al (1997, 2000) may indeed have
been a displacement behavior, although the
authors suggest only that the yawns indicate
acute and/or chronic stress.

Pacification behavior, or behavior presented
to show friendliness or suppress aggression in
another individual, is the other sub-type of
social yawn (Abrantes, 1997). As social stmcture
evolved in the wolf ancestors of dogs,
individuals had to adapt to living, hunting, and
feeding in close proximity to other highly
aggressive individuals (Dunbar, 1979). Fight
avoidance was evolutionarily advantageous
because fighting wastes energy and can result in
serious injury. Certain behaviors arose to
bypass aggression and show friendly intentions.
A dog will perform pacification activities to
suppress the aggression it perceives in another
individual, either dog or human. Rugaas calls
pacification behaviors "calming signals" and
explains the importance such signals have in
maintaining harmony and avoiding conflict in
wolf and dog social groups. Pacification yawns,
therefore, are perfonned to change the behavior
of another individual. The difference between
displacemènt and pacification yawns is
very subtle, and depends on the context the yawn
occurs in.

Most dogs easily learn at least a few words
of the human language. Basic obedience training
relies on the dog's ability to learn to
recognize and distinguish between commands such
as Sir, DOWN, COME, and STAY. One of the first
words a dog learns to respond to is its own
name. The responsible dog owner should in turn
learn to decipher the signals the dog presents
to him or her. When a dog becomes anxious and
nervous at the veterinarian's office, perhaps
the owner could give an exaggerated yawn,
promoting calm and relaxation in the dog's own
language. Dog trainers could watch for yawns to
know when they have pushed a dog too far and
should maybe try a new training approach. Taking
advantage of the acute canine awareness of body
cues, and using more non-verbal signals, might
lead to more effective training. Rugaas relates
that, "In many cases dogs become hysterical when
I answer them in their own language." Yawns
could also be used to index stress levels in
shelter dogs. Therapy or assistant dogs that
suddenly engage in a spate of yawning are not
indicating boredom, but rather that they are
uncomfortable in a given situation. Many
applications exist for this one, simple
behavior.

CHAPTER 2

Methods

To test the hypothesis that dogs perform
more rest yawns than social yawns, an
observational study was designed. Preliminary
observations indicated that all dog yawns are
morphologically similar; therefore, the context
of a yawn was used to categorize it either as
rest or social. Both pacification and
displacement yawns were categorized as social
yawns.

Many of the yawns that occur in the animal
world may not be true yawns, but rather gaping
of the mouth (Baenninger, 1987). True yawns have
two components: mouth movement and respiration.
A true yawn involves wide opening of the mouth
accompanied by deep, slow inspiration and a more
rapid expiration (Baenninger, 1997; Deputte,
1994; Provine et ai, 1987a; Smith, 1999). At
times the dogs I observed gave quick mouth
gapes. I did not count these as yawns because
they lacked the respiratory component of true
yawns. Only yawns consisting of both basic parts
were considered yawns in this study. Other
components of the yawning reflex in dogs were a
lowered head, ears pulled backwards, exposure of
the teeth, and eyes partially or fully closed.
All dogs exhibited these traits while
yawning.

I decided rather than observe individual,
isolated animals, I would watch dogs that were
interacting with other dogs or people. Beerda et
al (1997) found that stressful stimuli elicited
yawns from dogs only when an experimenter was
present. During stimuli given while the dog was
alone, no yawns occurred. The presence of
another individual seems integral in stimulating
yawning. A study on infant canid behavior
indicated that the presence of another animal
serves as a stimulus for both yawns and
play-soliciting (Bekoff, 1974). With this in
mind, I chose two social situations from which
to make my observations. All observations were
made at the Canine Learning Center in Fort
Coffins, Colorado between November 2000 and May
2001.

One type of situation studied was canine
daycare. During the day owners left their dogs
at the CLC facility under the supervision of the
CLC staff. The dogs were allowed to play and
interact with each other. I recorded data during
Monday, Wednesday, and Friday daycare sessions.
Most owners did not bring their dogs to daycare
everyday, so I had only partial overlap of dogs
on the three different days. Dogs ranged in age
from four months to ten years old. A wide
variety of dog breeds were represented,
including Labrador and Golden retrievers,
Huskies, several breeds of terrier, German
shepherds, a Doberman Pinscher, Great Dane, and
several mixed breeds.

Observations were made between 8:00 and
11:30 in the morning during intervals of two
hours. I found that two hours was the length of
time I could keep my attention on the dogs
without becoming distracted. During these
morning daycare sessions, the dogs were kept
off-leash in a large room and were free to move
about as they chose. Some dogs played with
others, some preferred to chew on toys or stay
off by themselves, still other dogs napped. A
wide variety of behaviors and interactions
occurred during the observation intervals. At
noon all dogs were kenneled and allowed a time
of rest.

A second situation that provided dogs with
social interaction was obedience class. All
classes observed were held at the Canine
Learning Center. The different classes I
observed were Puppy Prep, for dogs between the
ages of four and eight months, and beginning and
intermediate obedience for dogs older than four
months. Classes are open to all breed types,
although class size is limited to 12 dogs. All
obedience classes were held in the evening
between 5:00 and 9:00 PM. Also important to note
is that I made observations only during the
first night of each class. After the initial
experience, dogs became accustomed to the CLC
facility, the instructor, and the other dogs in
class. I wanted to observe the dogs' reactions
on the first night of class while the situation
was new to them.

Dogs were exposed to two different social
settings during obedience class. When owners
first arrived with their animals they waited for
a brief time in a small waiting room measuring
400 square feet Figure la shows the waiting room
and its seating arrangement. By the time class
began, the room was full of 10-12 dogs
accompanied by their owners. Little space
remained between dog-owner pairs.

Once class started, the owners and their
dogs moved into a 1800 square foot exercise
room, and all pairs were free to spread a
comfortable distance apart. Figure lb is a
photograph of the exercise room. Each class
lasted for 60 minutes. During class, dogs were
no longer under the stress of a high-density
situation. Instead, dogs were asked to perform
new behaviors in a strange room with different
dogs, people, and new smells. The dogs were
exposed to novel sensory input, while at the
same time being expected to perform at a high
level of concentration and control.

After choosing the observation settings, I
then developed a method for recording observed
yawns as useful data. My goal to was to observe
as many dogs as possible, and by the end of data
gathering I had watched a total of 84 dogs. Each
dog was followed individually for 15-20 minutes.
Before I started observation of a dog, I
recorded the date, type of session (daycare or
obedience class), and the naine of the dog, as
well as its age, sex and breed. This information
was recorded on a check sheet, a new sheet for
each animal (see appendix A). If the age or
breed of a dog was unknown before observation, I
checked the dog's records before leaving the
CLC.

At the end of each observation segment, the
average activity level of the dog was recorded.
Activity level was based on a scale of 1 to 5,
with 1 representing extremely low physical
activity. Values were assigned based on the
following definitions for each level.

Dog is sleeping or, if awake, lying down.
Did not stand up during the observation
period.

Dog spends majority of the observation time
in a lying or sitting position. Brief periods of
standing or walking.

Equal time spent between standing, walking,
running or playing and sitting or lying down.
Also includes dogs with high 'excitement levels
but that are being restrained from moving by
collar, leash, or the owner's body.

Majority of time spent walking, running, or
in play. Brief periods of sitting or lying. 5-
Entirety of observation time spent running or
playing with others. Did not sit or lie down
during this time.

Because I could not discriminate between
rest yawns and social yawns based on physical
appearance, I needed to somehow record the
context of the yawn. While watching each dog, I
kept track of yawn behavior using the
aforementioned check sheet. This sheet was
basically a checklist of behaviors based on an
ethogram developed for this study. The ethogram
consisted of behavioral states - such as lying
down or walking and behavioral events. Events
occur in a shorter time span than states and
reveal more about the dog's motivations. For
this study, the ethogram focused on activities
presented for pacification or displacement, and
some behaviors related to anxiety and play. The
different behavioral states and events were
defined as follows:

BEHAVIORAL STATES

Sleeping - Lying down, head resting on
ground or paws, eyes closed.

Lying Down - Middle section of body in
contact with the ground or floor.

Sitting - Hind end in contact with the
ground or floor.

Standing - Body in upright, stationary
position.

Walking - Movement without an in-air phase.
In other words, at least one paw is touching the
ground as the dog moves.

Trotting - Movement with an in-air phase
where the hindlegs do not extend forward past
the midline of the body.

Running - Movement with an in-air phase
where hindlegs extend forward past the midline
of the body.

BEHAVIORAL EVENTS

Head Turn - Head turned away, thereby
breaking eye contact with the individual
approaching or interacting with the dog. The
movement can be a slight adjustment, or the bead
can be moved fully to the side. In some cases,
turning the head may result in the dog looking
forward. For instance, a dog sitting by his
owner's side must turn his head towards her to
look at her. When turning the head away to break
eye contact, the dog might look straight forward
or in the direction opposite the owner.

Hip Nudge - The dog approaches another
individual, turns around, and gently bumps them
with the hip or backside.

Licking - Dog licks another dog usually
around the mouth and muzzle, or licks a human,
often on the hands or face. Licking movements
can also occur when no other individual is
near.

Muzzle Lick - A quick movement of the tongue
in which the dog licks his own nose or muzzle.
Dogs also will lick around their mouth after
swallowing, so care must be taken to distinguish
if the lick was reflexive or communicative.

Muzzle Nudge - One dog gently nudges its
muzzle against the muzzle of a second dog. This
behavior can also be directed towards humans,
with the dog using its muzzle to nudge a
person's hands or legs. Dogs may also nudge at
the air when no other individual is in close
proximity.

Pawing - Paw lifted to touch someone or
something. A dog might paw the air if the
individual the movement is intended for is a
short distance away.

Play Bow - A play solicitation movement
where the front part of the body is positioned
as if lying down, while the back end sticks up
in the air.

Submissive Crouch - Body held low to the
ground, tail is lowered or tucked between the
legs, and the ears lowered or flattened.

Stretching - Front legs extended while the
muscles are flexed, followed by extension and
stretching of the hind legs.

Turn Away - Dog turns its side or back to
another individual. Similar to the head turn
except that the entire body is moved.

Space was left on the check sheet for
additional behaviors to be added, for instance
barking, whining, panting (rapid inhalation and
exhalation with the mouth open), and
leash-pulling (the dog strains against his
collar while being restrained). Each behavior
listed was followed by a column for 'before' and
'after,' for recording the behavior that
occurred before and after the yawn. Room was
left at the bottom of the page for any comments
about the observed yawns. I often made notes in
this space about the context of the yawn or
information about the dog, for instance if it
was his or her first day at daycare.

The majority of daycare observations, and
all obedience class observations, were made in
person. Five daycare sessions were video taped
and reviewed at a later time. Taped observations
were recorded the same way as real time
observations were made. Each dog was followed
for approximately 15 minutes with the
camera.

During daycare a small area at the front of
the exercise room was fenced off with three foot
high metal fencing to prevent the dogs from
interacting directly with the staff members.
Figure 2is a photo of the front of the room and
the fenced space. I made my daycare observations
from this fenced area. For obedience classes, I
sat on a bench in the corner of the exercise
room. Inevitably, a person or dog would
sometimes block my line of vision. When this
happened I simply waited for the obstacle to
move. If a minute passed and my view was still
blocked, I changed my own position, either by
standing up or moving over to one side.

When a dog I was watching yawned, I recorded
the behavior that occurred during the 10 seconds
before and the 10 seconds after the yawn. A more
active state took precedent over a less active
one. For example, if a dog was walking around,
then sat down and yawned, I recorded the before
activity as 'walking.' Also, an event was
recorded over a state. Following a yawn, a dog
in a sitting position who then gave an
identifiable head turn was recorded as 'head
turn' in the after column. If two events
occurred before or two occurred after the yawn,
the event that happened in closest proximity to
the yawn was recorded.

I used numbers in the before and after
columns to indicate which yawn corresponded to
which set of behaviors. For instance, a dog who
was lying down, yawned for the first time, and
then got up and walked around would receive a
number one in the before column of 'lying down'
and a number one in the after column of
'walking.' The second yawn would be designated
by the number two, and so on.

After months of observations, and review of
the video tapes, I went through the checklists
and classified each yawn as being social or
rest. This task was a complicated matter, so I
developed criteria for classification and
maintained consistency as I went through the
data. I had to first decide what combination of
behaviors indicated a rest yawn. During my
background research, I had determined that rest
yawns occur during transitions in arousal level,
either going from activity to rest or vice
versa. Therefore, transitions in states were
considered rest yawns. For example, a series of
lying down yawn - sitting - walking was
classified as a rest yawn. Likewise, a dog that
spent time playing, sat, yawned, and laid down
was also considered to have given a rest
yawn.

A yawn that occurred during a low activity
state, such as lying down or sitting, and did
not occur in conjunction with an event, was
recorded as a rest yawn. This criteria included
dogs that were lying down or sitting both before
and after a yawn and engaged in no other
activities or behaviors.

A few exceptions were made to the rest yawn
criteria. If a dog was sitting, yawned, and
continued sitting, yet it was clear his
attention was on another individual, I
considered this a social yawn. A good example of
this situation was a male Golden retriever named
Max. Max was lying down when two dogs who were
playing ran into him. Max yawned, facing them,
but did not change position or give any other
behavior that I could perceive. In cases such as
this, I made notes about the context of the yawn
if I felt confident it was directed toward
another individual and not merely arousal
reflex.

Social yawns were defined as being proceeded
or followed by an event. Some yawns had event
behaviors both before and after. The events I
used for this study were communicative
behaviors, so I considered yawns to have a
social function when they occurred in
conjunction with these behaviors. Instances of
social yawns included a German shepherd who
turned his head away from a growling dog,
yawned, then gave a muzzle lick, and a Labrador
Retriever who was standing off by herself but
yawned and turned her head away from a dog who
approached her and solicited play. In these
examples the muzzle lick and head turns were the
behavioral events.

Stretching was the one event that, when
occurring along with a behavioral state, did not
result in a yawn being considered social in
nature. The stretching reflex appears to
accompany yawning in dogs (Baenninger, 1997) and
is a primitive component of the waking phase
(Provine et ai, 1987). Stretching while
transitioning from rest to activity parallels
the arousal mechanism of rest yawns.

Dogs that did not yawn were included, along
with the dogs that did yawn, in the data
analysis. Analysis was done using Minitab
statistical software. Because my data was
normally distributed, as confirmed by the
Ryan-Joiner test for normality, I used
parametric tests to analyze the data. For all
tests, a value of alpha = 0.5 was used to
determine significance.

A one-way analysis of variance was employed
to test for equality between the mean number of
all yawns in general, social yawns, and rest
yawns in each activity level. A Pearson
r-correlation and regression analysis was used
to determine if activity was a reliable
predictor of the two different yawn types, as
well as yawns in general.

The ANOVA test was also used to detect any
differences between age group and mean number of
yawns. In looking at the effects of age and
session type on yawning, a two sample t-test was
utilized, since only two means were being
compared.

Finally, to test the hypothesis that rest
yawns occur more often than social yawns, a
paired t-test was performed over all the data.
The paired t-test was also used on data from
daycare and obedience classes separately.

CHAPTER 3

Results

Of the 84 observations made, both in-person
and videotaped, 35 were made during daycare, 49
during obedience classes. Out of 84 dogs, 44
were female and 40 male. The dogs ranged in age
from puppies of 3 months to a bitch of 9 years.
Thirty dogs were under one year of age, 37 were
one year old or older, and age was unknown for
17 of the dogs (see Appendix B for all subject
data). Before data analysis, ages were clumped
together in three groups. Group 1 contained dogs
less than one year old ( = 30). Dogs from one
year of age up to three years of age fell in
Group 2 (g = 18). Finally, Group 3 were dogs
three years or older (g = 19).

The number of breeds represented in this
study was 33, accounting for 63 of the dogs. The
remaining 21 dogs were either a known mix of
breeds or an unknown mix and classified simply
as "mixed breed." The most common dogs seen were
Labrador retrievers, German shepherds, and
Golden retrievers, in that order. This
representation is not surprising given the
current popularity of these three breeds in
North America.

An activity score of 3 was the most common
level of activity seen, as displayed in Table 1.
Only one dog actually scored a 1; she slept
during the full fifteen minutes she was
observed. No dogs were classified at an activity
level of 5, meaning that no dogs ran and played
for the entire observation interval. All dogs
spent at least a short time sitting or
lying.

A total of 149 yawns were recorded during
this study. Of the 84 dogs, 63% (53 dogs) yawned
during their observation interval. The one dog
who slept during her entire observation time did
not yawn at all. Dogs that were at an activity
level of 2 had the highest percentage of yawns
at 72%, followed by the more active Level 3 dogs
of which 68% yawned. Only 29% of the dogs active
enough to score a 4 actually yawned.

The mean number of yawns given, when
averaged over the total number of dogs observed,
was 1.3 yawns per dog. As an observer, what
interested me were the above average yawners.
Just as some dogs never yawned, others yawned
quite frequently. I saw several dogs that gave
multiple yawns during very short time periods.
One of these dogs was a female Labrador
retriever named Cocoa. She had been lying on the
floor napping. As she woke up- first lifting her
head up, then mouth wrestling with a dog lying
near her- she gave a series of five or six
yawns, all within a ten minute time span. These
were classified as rest yawns since she was
transitioning from sleep to activity.

Another example was a female mixed breed
puppy of four months. While waiting with her
owner for her first puppy prep class to begin,
she yawned a total of five times in less than
fifteen minutes. During this time she pulled on
her leash, barked and showed much agitation and
excitement.

The waiting area seemed to be a stressful
scene for dogs of all ages. Another dog, a five
year old male greyhound, yawned five times in
the first seven minutes of observations. As he
waited with his owner, other dogs were arriving
for class and his owner continually bent over
him, put her arms around him, and kissed and
stroked his head.

The most frequent yawner was a female
English setter mix. She yawned a total of eight
times during her observation interval. Most of
her yawns were given while standing or walking
around. She paced around the room, weaving in
out of clusters of playing dogs, and yawned as
she passed them. In another instance, a dog who
was playing ran into her where she stood and she
looked away from him and yawned.

While I saw individual dogs give multiple
yawns, these yawns failed to induce yawns in
others around them. Even when a dog yawned
several times in close proximity to another dog,
the other dog did not start yawning. Cocoa, the
Labrador retriever mentioned before, was giving
her series of yawns right in the face of a
Golden retriever lying next to her. The
retriever, however, did not yawn even once. I
saw no evidence of yawn contagion between the
dogs I watched. Human yawns, meaning the yawns
emitted by myself or employees of the CLC, also
did not result in yawns among the dogs.

Some of the situations in which yawns were
observed stood out to me, either by being
unexpected or very consistent in causing yawns.
An example of an unexpected yawn was a female
Belgian turverin, 18 months old. She was a very
active dog and spent most of her fifteen minutes
playing and interacting with other dogs. At one
point she moved away from the others and laid
down against the wall for just over a minute,
still alert and watching the other dogs playing.
She then yawned and a few seconds later got to
her feet and began chasing her old playmate.
Because I could not determine that she had
directed her yawn at another individual, I
considered the yawn to be a rest yawn. She
transitioned from high activity to resting in a
lying position, back to high activity, and gave
no sign of displacement or pacification.

Still other situations were not so
unexpected, but rather very consistently tied to
yawns. The daycare dogs often gathered around
the fenced off area at the front of the exercise
room. During this time the dogs are pressed
close to each other, all trying to push to the
front. The dogs are facing the same general
direction and looking up at the gate and more
often than not at least one of the dogs would
yawn. Figure 3 is a photo of the dogs gathered
around the fence. The Labrador retriever to the
right of center is yawning.

The situation that most consistently
produced yawns involved owner-dog interaction.
During obedience classes, both in the waiting
room and in class, many of the dogs were excited
and aroused by their new surroundings. In an
effort to calm and restrain their pet, the owner
often would physically force the dog into a SIT
or DOWN position and hold them there by pulling
on the dog's collar or by pressing on the dog's
body. Still other owners wrapped their arms
around the squinning dog, held them in their
lap, or continually said the dog's name and told
it to SIT or calm down. Dogs who were physically
restrained in this manner yawned a great deal.
Most of the yawns I observed during obedience
class were emitted by dogs being tightly
restrained by their A one-way analysis of
variance was performed on the number of rest
yawns for each activity level and indicated no
significant difference. Also insignificant were
the number of social yawns given 1» each
activity level.

To detennine if a correlation existed
between the activity level of a dog and th

number of yawns exhibited or if the two are
independent of each other, a regression analysis
was performed. Because activity level was a
qualitative trait, dummy variables were created
so that both activity level and number of yawns
were quantitative data. Figure 4 is a fitted
line graph using a cubic regression model. This
graph helps to illustrate the pattern of yawning
seen in this study. However, activity level was
not a reliable predictor of number of
yawns.

No significant correlation existed.between
activity level and the number of social yawns.
The occurrence of social yawns appears to be
independent of the animal's level of activity.
Rest yawns also were not significantly affected
by activity level.

Observation session and number of yawns To
test whether dogs yawned more during
observations made in daycare or obedience, a two
sample t-test was performed.

The mean number of yawns during daycare (M =
2.11, = 2.08) and all three types of obedience
class (1 = 1.53, = 1.71) did not vary
significantly, t(64) = 1.36, = 0.18. The two
situations elicited a similar number of yawns
from dogs.

In looking at specific yawn types, a two
sample t-test revealed no significant difference
between the mean number of social yawns given
during each session. The same test was also
performed for the mean number of rest yawns.
Averages for rest yawns made during daycare (M =
0.77, SD = 1.21) in comparison to those made
during obedience classes (M 0.22, = 0.51) did
differ significantly from each other, t(42) =
2.5 1, p = 0.016. Rest yawns were more likely to
occur during daycare than during any of the
obedience classes.

Sex of the dog and number of yawns The
number of male and female dogs in this study was
almost equal and I was curious to see if either
gender yawned significantly more than the other.
A two sample t-test was performed on the mean
number of yawns for males (M = 1.48, SD = 1.50)
and females (M = 2.05, SD = 2.16). No
significant difference was found between the
sexes, t(76) =1.42, p = 0.16. Thus, females
yawned just as often as males and vice versa. In
this study, all males over eight months of age
were neutered and the majority of females were
spayed.

Age of dog and number of yawns A broad range
of ages were represented in this study. Although
30 dogs were under one year of age, the number
of dogs in each one year interval alter age one
were more normally distributed. Because of the
overrepresentation of puppies, dogs were
clustered into three groups based on their age.
Group 1: dogs less than one year old, Group 2:
dogs one year old up to, but not including,
three years of age, and Group 3: dogs three
years old or older.

The effect of age on yawning frequency was
analyzed using a one-way ANOVA, as illustrated
by Figure 5. As shown by the boxplot, the mean
of all three groups did not vary a great deal.
The ANOVA test revealed no statistically
significant difference between the mesh number
of yawns for each age group, F(2, 64) = 0.59, p
= 0.559. The ages of 17 of the dogs were
unknown. These dogs were not included in this
part of the analysis.

Frequency of each yawn type A total of 111
social yawns (M = 1.32, SD = 1.69) and 38 rest
yawns 04 = 0.45, SD = 0.91) were recorded over
the course of this study.

Intuitively this difference appears to be
substantial. Analysis using a paired t-test on
the data for the number of social vs. rest yawns
verifies a statistically significant difference
between the two means, t(84) = 4.08, p<0.001.
Figure 6 is a histogram showing the differences
in number of social and rest yawns. Positive
numbers on the x-axis indicate more instances of
more social than rest yawns, negative numbers
more rest than social. Frequency on the y-axis
refers to the number of dogs within each
difference. The circle labeled Ho represents the
null hypothesis for the t-test, that the
difference between the mean number of social and
rest yawns should be zero. The difference
measured in this study was actually 0.87, as
indicated by the circle labeled x-bar.

To determine if social yawns also occurred
with a higher frequency than rest yawns during
either daycare or obedience class, I analyzed
the two types of yawns in each session. For the
data gathered during daycare, the difference
between the means for social and rest yawns was
small and a paired t-test showed the difference
to be insignificant. However, during obedience
class, the mean number of rest yawns (M = 0.224)
when subtracted from the mean for social yawns
(M 1.3 1) was indeed statistically significant,
= 3.98, p <0.001. So, overall we sec a
difference in the number of social and rest
yawns, the difference coming mainly from
obedience class observations.

CHAPTER 4

Discussion

Behavioral studies performed on animals have
one unavoidable problem: at no point can we ask
the animal what it was thinking when it
performed the behavior. The challenge is in
distinguishing communication-related behavior
from normal behavior patterns (Maestripieri et
ai, 1992). Julie Yamane, the owner of the CLC,
would sometimes use her adult male Belgian
turverin as a demonstration dog while teaching
her obedience classes. The dog's name was Jordy,
and when she brought Jordy into the room with
the rest of the class he consistently yawned at
least once. Several possibilities exist for why
Jordy yawned. Perhaps he was sleeping in his
kennel before Julie brought him into the room
and was in the process of transitioning between
rest and activity. Or, being a large, dominant
male dog, perhaps he sensed the discomfort his
presence caused in some of the more submissive,
low confidence dogs in the class. In this case,
his yawns were for pacification purposes, to
indicate he intended no threat. A third
possibility is that Jordy himself was
uncomfortable. Some of the training techniques
Julie demonstrated included how to stop problem
behaviors, such as a dog that jumps up on
people. Using Jordy, she demonstrated how to
stick your knee out when the dog jumps up. Jordy
got to the point where he anticipated this event
and would no longer put his forefeet upon her at
this point in the demonstration. Being the demo
dog meant he had to perform some behaviors he
was uncomfortable with. Unfortunately, I could
not question Jordy about the motivation behind
his yawns, nor could I ask any of the other dogs
in this study. Instead, I had to rely on the
situation and surroundings the dog was in. In
this way, differentiating between rest and
social yawns was very much up to my own
discretion, although after watching so many dogs
I felt confident in distinguishing one yawn type
from the other based on contextual cues.

One comment should be made about the
classification of some of the rest yawns. As
explained in Chapter 2, a dog that yawned while
moving from an upright position to a sitting or
lying position was considered to have given a
rest yawn. Rugaas suggests that sitting down or
lying with the belly against the ground is a
signal used to calm other individuals, in which
case a yawn performed along with these movements
might have been social. Because detennining the
motivation behind sitting or lying down was too
difficult, I did not account for this
possibility in the study. Yawns were considered
social only when paired with other, less
ambiguous signals, or when the yawning dog was
clearly interacting with another
individual.

In categorizing the dogs into various
activity levels, I was not surprised to find
many of the dogs I watched falling into Level 3.
The criteria for this group seem to fit the
behavior pattern of most dogs. During play, the
dogs were very active for a time, then the game
would break up and the dogs w9uld separate,
usually going off to sit or stand until a new
play session was initiated. This alternation of
activity and "down time" was part of the
qualification for activity Level 3. Also falling
into this category were many of the obedience
class dogs. On the first night of class dogs
were anxious to greet and sniff the new dogs
around them. I saw many instances of play
solicitation between newly introduced dogs.
Under normal circumstances these dogs might have
fallen in Level 4, but because they were
restrained by their owners, their energy was
somewhat contained, and they were placed in
activity Level 3.

Out of the 84 dogs, only one dog was
classified as activity Level I due to the fact
she slept through her observation period. This
dog was a female Husky who was afflicted with
epilepsy and on a prescription drug to control
her seizures. One side effect of the drug was
lethargy, and she slept the majority of her time
in daycare. Her complete lack of yawns should
not surprise us. While sleeping, she was not
performing any activities, let alone yawning.
Also, if we believe the arousal hypothesis, she
was remaining in the same arousal state while
slumbering, so yawning to stimulate the brain
for activity was not necessary. To explain the
absence of yawns during sleep, Baenninger (1997)
states, "This is what the amusai hypothesis
would predict, since the struggle to maintain
wakefulness has been abandoned by a sleeping
individual."

On the opposite end of the spectrum from the
non-yawners were the dogs that kept yawning
again and again. The multiple yawns I observed
in dogs were sometimes rest yawns, as in the
case of the Labrador retriever mentioned in
Chapter 3 who yawned continually while waking up
from a nap. In other instances, a set of yawns
had a communicative function. Examples of
multiple social yawns were seen in the obedience
class dogs who yawned multiple times ithin a
period often minutes. In either type of multiple
yawn, after a first yawn was given, others
followed in close proximity. In Baenninger's
study (1987) on yawns in different vertebrate
species, he found that lions did not give
multiple yawns, but that mandrills occasionally
repeated their yawns after a few minutes. His
study illustrated that the capacity for multiple
yawns differs from species to species. I found
it also differs within a species, for instance,
between individual dogs. Not all of the subjects
in this study gave multiple yawns. Yawning
frequency varied greatly in the dogs I observed.
One explanation for the variation of social
yawns is that some individuals are more adept at
handling novel, potentially stressful
situations. Certainly not all the dogs present
in the crowded waiting room yawned.

Although multiple yawns were observed from
the same individual, multiple yawns did not
occur between individuals. I saw no evidence
that witnessing the yawn of a conspecific
elicited a yawn from a dog. This phenomenon of
yawn contagion is present in the human yawn
reflex. Seeing, hearing or even thinking about
yawning can stimulate yawns in humans
(Baenninger, 1997). Reading this discussion may
have elicited yawns from the reader. Humans seem
to be the only species that show this trait;
social contagion of yawns is absent in other
species that yawn (Baenninger, 1987; Smith,
1999). Based on this information, I did not
expect to see yawns of a contagious nature among
the dogs. Indeed, the dogs yawned independent of
each other. Dogs in close visual proximity to a
yawning individual were not seen to yawn
themselves. This lack of contagion was a benefit
to the study, as detennining if a yawn was
induced by contagion or arose independently
would have been impossible. Perhaps if human
yawns had a communicative funtion we also would
not show yawn contagion.

Another unexplained observation made during
this study was the yawning by dogs facing the
gates at the front of the room. Dogs that yawned
in this situation were usually looking forward
through the gates. It appeared their attention
was fixed on whatever was beyond the gate.
Because of this focus, I was convinced the yawns
were directed at whoever or whatever had caught
their attention. When someone entered the
exercise mom, a short episode of mass hysteria
ensued. Some dogs, in their excitement, would
jump up on the fence and be scolded and sprayed
with a water bottle until they complied and had
all four feet back on the ground. Perhaps these
yawns were given in anticipation of the period
of excitement and, at times, disciplinary action
that might follow.

A second possibility for social yawns in
this situation was the need for signals that
displace aggression among individuals in such
close proximity. Reduced personal space
increases the occurrence of agonistic behavior
in some dogs, in which case yawns might occur
for purposes of pacification in an effort to
prevent such outbreaks. Ten to fifteen dogs
standing on top of each other is a situation
bound to cause social discomfort in some
individuals. Displacement yawning may result.
Besides waiting at the gate, restraint by the
owner was the other situation in which I
commonly saw yawns. The physical restraint
observed here was more than just a human holding
one end of a leash and not allowing the dog to
go where it wanted. This restraint was more
forceful and involved the owner holding directly
onto the dog's collar or body. Smaller dogs were
sometimes picked up and held in the lap. Owners
wrapped their arms, even their legs, around
larger dogs. In some cases, the social yawns
performed in this situation were displacement
activities. Dogs that were uncomfortable around
strangers and had intentions of fleeing the
situation were denied the opportunity to escape.
A female German shepherd that was fearful of
other people and dogs continually tried to pull
away from the other class members. Her owner
would then pull the dog back until the shepherd
was again sitting at the owner's side. This tug
of war continued while the dog yawned five times
in response to being asked to behave counter to
her internal motivation.

Pacification was the other motivation behind
the yawns of some of the restrained dogs. The
dogs were restrained primarily because their
high levels of arousal and excitement made them
uncontrollable. As a dog continued its wild
behavior, the owners arousal levels also
increased. Frequently the owner's voice would
become more commanding and angry, the restraint
on the dog more physical. This mounting
aggression alone could elicit pacification
behavior from a dog. In restraining their dog,
owners engaged in behaviors they may or may not
have realized were very dominating. For
instance, owners would lean over the dog's body,
placing their hands on top of the dog's head or
muzzle. Pacification yawns were given by some
dogs in response to the dominant postures of
their owners.

After analyzing the data, many variables
were shown to have no effect on the frequency of
yawns overall. The first factor examined was
activity level. Yawns occurred in Levels 2
through 4 as arousal levels changed or as dogs
gave communicative signals. Because either yawn
type was possible, we can expect that activity
level would not significantly effect yawn rates.
This expectation was supported by the data.

Dogs communicate with each other any time
they are not sleeping, so social yawns should be
observable across various levels of activity. In
fact, this prediction was true, and the average
number of social yawns in activity Levels 2, 3,
and 4 was very similar. The expectation for
frequency of rest yawns, however, was that they
should be dependent on how active the dog was.
In human studies, subjects who showed the lowest
frequency of yawning were more active in their
daily lives than high frequency yawners were
(Baenninger, 1997). From this information, we
might predict that rest yawns in dogs should
increase as we move from high to low activity
levels. The data in this study did not show this
effect, and rest yawns did not vary
significantly between activity levels. In his
in-depth discussion of the functions of yawning,
Baenninger (1997) explains that carnivorous
mammals fluctuate widely between arousal levels,
from low energy resting states, to hunting and
killing prey items. He suggests that carnivores
would need to have methods that allow them
frequent shifts between arousal states. The rest
yawn might serve this purpose, and dogs, being
carnivorous, would show more frequent changes in
arousal level than might be expected based on
common sense.

In designing this study, I chose to observe
settings that provided ample opportunity for
social interaction between my canine subjects.
Both the daycare and obedience classes were rich
with potential dog and human stimuli. Analysis
showed no difference in overall yawns between
the two session types, meaning that whatever
stimuli elicited yawns was present in both
settings. In daycare, dogs interacted primarily
with conspecifics. The reverse was true of
obedience class. During obedience training, the
human-canine interaction predominated, but in
both settings, dogs were presented with social,
stimulating situations. I chose these settings
with the expectation that they would elicit
social yawns. I was not disappointed, and
average numbers of social yawns did not vary
significantly between the groups.

While obedience class provided dogs with
plenty of dog-dog and human-dog interaction,
little time was available for sedentary,
low-energy behavior. In contrast, daycare dogs
were free to be as active or inactive as they
chose. Dogs adapt very well to human routine,
and daycare dogs are no exception. Every day at
noon, the daycare dogs were kenneled and allowed
to nap for a few hours. I noticed while making
my observations that around 11:00 or 11:30 am,
many of the dogs became restful. Less animals
were involved in play; the majority were sitting
or lying down on the floor. Whether this
behavior was in anticipation of "nap time,"
because the dogs were tired from the morning's
exertions, or a combination of the two, I do not
know. At any rate, daycare dogs had ample time
available to them for rest and relaxation.
Because of this difference between daycare and
obedience classes, I expected more rest yawns
would appear during daycare observations.
Statistical analysis showed support for this
prediction. The average number of rest yawns
seen in daycare compared to those seen in
obedience classes was significantly
different.

One of the criteria the CLC upholds for its
daycare program is that all male dogs over the
age of eight months must be neutered and intact
females must be kept home while in heat. Because
of this rule, all the sexually mature males I
observed were neutered and all but a few of the
females were spayed. No significant difference
was shown to exist between the mean number of
general yawns of male and female dogs. In
non-human primates, such as mangabeys and
macaques, males were found to yawn over six
times more frequently than females (Deputte,
1994). The absence of sex hormones in my canine
subjects would undoubtedly rule out this
effect.

Looking to canine social structure provides
another possibility. The social hierarchy in a
dog pack is two-part system with separate
hierarchies for males and females. In sorting
out dominant and subordinate relationships among
themselves, female dogs would need to
communicate with each other just as much as male
dogs. This scenario is a possibility, albeit a
weak one. The emphasis on pack structure is
greatly reduced in the domestic dog due to their
more stable, predictable lives (Dunbar, 1979).
The domesticated dog is no longer in a life and
death struggle with nature. Also, the majority
of the dogs I observed in this study did not
have issues with dominance.

After reviewing the literature on yawning
and researching canine social behavior, I
expected not to find an effect of age on yawning
frequency. Puppies raised with their litter
learn pacification behaviors early on to prepare
them for interaction with adult dogs. Also,
pacification activities can be given by dominant
or subordinate individuals of any age to show
that no threat is intended, or to avert
aggression (Coren, 2000). Dogs of all ages find
themselves in situations that cause nervousness
or stress. A trip to the vet's office, the loud
noises from the construction site next door,
being handled by the groomer, all of these
situations can stimulate displacement yawns. The
results of this study indicated that no
significant difference existed between the age
groups of the subjects. Dogs under the age of
one gave a similar number of yawns to those dogs
between ages one and two, and dogs three years
old or older.

The paired t-test confirmed that the
difference between the number of social yawns
and rest yawns was significant. However, the
difference was the opposite of the original
hypothesis. Social yawns were given more
frequently than rest yawns, as opposed to the
prediction of more rest yawns than social yawns.
Part of the reason for this finding was
undoubtedly the situations I chose to observe. I
picked out social settings that would provide
dogs with ample interaction. Obedience classes,
even more than daycare, were high stress, high
arousal situations for the dogs. Naturally I saw
more communicative behaviors than rest related
activities. If observations had been made in the
dog's home or even among a small group of dogs
who were already familiar with each other, I
predict I would have observed more rest yawns
than were seen in this study.

Overall, a difference existed between social
and rest yawns, but did each observation session
contribute equally to the discrepancy? Analysis
of the daycare data indicated that social and
rest yawns were emitted in similar numbers. As
mentioned before, dogs in daycare had more
chances to sit or lie down and shift their
arousal levels up and down. This flexibility
increased the number of rest yawns I observed,
making rest yawns more even with social yawns.
Also, nearly every dog in daycare attended
regularly, and was therefore familiar with the
routine and with the other daycare dogs. I had
the opportunity to watch two or three dogs on
their first day of daycare. One dog was very
agitated and whined and pawed at the fence most
of the time. Another dog joined right in with
play and chase games. These individual
differences reiterated that some dogs take novel
situations in stride, while others become
stressed.

The obedience class dogs had far less
opportunity to relax and transition between
arousal level, resulting in yawns being skewed
in the direction of social yawns. Even more than
available rest time, the novelty of the
situation was a major influence on the behavior
of the dogs. The vast majority of dogs in these
classes had never met before. As well as being
around strange dogs, obedience class dogs were
exposed to more human contact than the daycare
animals. Owners introduced themselves and their
dogs and showed much interest in meeting and
petting other dogs in the class. A dog might not
only be physically touched by strange humans,
but he may also watch his owner give affection
to other dogs. Both scenarios can cause anxiety
in dogs. Obedience class was also the setting of
increased physical restraint and scolding of
overexcited animals, treatment that resulted in
a plenitude of social yawns.

Another factor adding to the stress of
obedience class was the class activity itself.
The dog and owner were interacting primarily
with each other, the owner asking the dog to
perform behaviors that were often new to both
members of the pair. The owner was challenged to
figure out how to lure the dog into the desired
position or behavior, the dog had to correctly
guess what his owner was asking him to do. I
myself have taken a dog through obedience class
before and realize it can be frustrating
learning new commands, as well as teaching the
dog to perfonn a behavior it has no prior
experience with. As an owner becomes frustrated,
his or her agitation shows itself in body
posture and in tone of voice. Dogs are naturally
in tune with body language and can detect these
signals long before the owner realizes she is
showing her frustration. Dogs confronted with
what they perceive to be an aggressive
individual respond with pacification behaviors.
While watching the interaction between dog and
human, I commonly saw dogs turn their head away
or give muzzle licks. Less often seen were
yawns. Although the yawns could have been given
to pacify the owner's agitation, they may
instead have been displacement activities
performed by a frustrated dog.

Because yawns consistently showed up during
certain situations, yawning behavior could be
used by owners to gauge the well-being of their
dog. Let us apply this knowledge to the
obedience class situation. An owner of a shy dog
might watch for excessive yawning as indication
of social discomfort in his or her dog. The
owner could then make adjustments to help the
dog feel more relaxed. For instance, the owner
could move a distance away from other dogs and
humans and perhaps perform some tricks with the
dog to focus the animal's attention on the owner
rather than on the surroundings. Rugaas suggests
the human himself use calming signals on a dog,
such as giving a big yawn while sitting with the
dog in a stressful setting.

On the other end of the spectrum, the owner
of a hyper, social dog might need to alter his
or her method of restraint An owner who feels
the need to hold the dog in his or her lap or
wrap their amis tightly around the animal may
only be adding to the problem. Dogs can
gradually habituate to being held tightly, but
at first it may be uncomfortable, even
threatening to the dog (Rugaas, 1997). Based on
this study, I would conclude that hugging a dog
tightly is a poor method of restraint, as
indicated by the high number of yawns elicited.
Instead, the owner again should try to focus the
dog's attention back on him or her using tricks
or treats. Weather permitting, dogs can even be
walked outside instead of waiting indoors. This
exercise serves to dissipate some of the dog's
excess energy and remove the over-stimulation of
the waiting room. The bottom line is that when a
dog is performing an increased number of yawns
outside of sleep/wake transitions, the
responsible owner should respond by helping the
dog to relax and calm down.

A certain satisfaction comes from having a
companion dog that understands and consistently
responds to trained commands. Conversely, the
human-canine bond can only be strengthened by
correctly understandiig and interpreting the
signals dogs use when speaking to us. The yawn
is a useful behavior to understand because it is
an obvious behavior that can easily be seen,
even from a distance. Another advantage is that
the yawn is an activity humans can also perform.
As Coren reminds us, "Yawning in public may be
viewed as a relatively meaningless (or impolite)
behavior among humans; it is conversation and
conciliation when used by or directed to dogs."
Perhaps in the future canine behavior
modification will utilize other non-verbal
signals from the canine repertoire.

Deputte,
B.L. (1994). Ethological study of yawning in
primates. 1. Quantitative analysis and study of
causation in two species of old world monkeys
(Cerocebus albigena and Macaca fascicularis).
Ethology, 98, 221-245.